A Syrian refugee has been shot in the head in a camp in Turkey as the number of those escaping their war-torn homeland soars to at least 150,000.

The Britain-based Syrian Observatory for Human Rights (SOHR) said the refugee was shot in the head by a Turkish officer in the Yelda refugee camp in Hatay province on the Turkish-Syrian border.

The officer was known for his mistreatment of refugees and had been suspended from duty following demonstrations against him in the camp, SOHR said.

"The atmosphere in the camp is very tense, many refugees are very angry at the humanitarian conditions and the treatment they face. Turkish officials are now trying to calm the situation," it said, although its claims could not be independently verified.

Rising number of refugees

Syria's neighbours, including Lebanon, Turkey, Jordan, and Iraq have been dealing with rising numbers of refugees in recent days.

Data from UNHCR, which counts only refugees who have registered or are in the process of being registered, shows a total population of 146,667 people. When unregistered refugees are taken into account, the number easily surpasses the 150,000 mark.

More than 50,000 refugees are in in Turkey and 6,000 new arrivals being recorded this week.

Most were from Aleppo and its surrounding villages. Syrians from Idlib and Latakia were also crossing the border to escape the violence. Children account for 72 per cent of the refugees.

There are nine refugee camps in Turkey and more are planned, the UN said.

In Iraq, there are 13,587 refugees, with new arrivals mostly from Syria's Kurdistan region. In Lebanon, 36,841 Syrian refugees are either registered or assisted, but many thousands have yet to register, UNHCR said.

In Jordan the number of refugees has reached 45,869 people, mostly from Dara'a and Homs. The UN has acknowledged the situation in camps there was "difficult".